TABLE 1.

Baseline characteristics of the study cohort

CharacteristicValue for age groupValue for all participants (n = 225)
2-4 yr (n = 73)5-7 yr (n = 52)8-10 yr (n = 51)18-25 yr (n = 49)
Gender (no. [%] of females)42 (57.5)25 (48.1)19 (37.3)30 (61.2)116 (51.6)
Ethnicity (no. [%])
    Bambara48 (65.8)26 (50.0)27 (53.0)33 (67.4)134 (59.6)
    Sarakole21 (28.8)23 (44.2)20 (39.2)13 (26.5)77 (34.2)
    Fulani3 (4.1)3 (5.8)3 (5.9)2 (4.1)11 (4.9)
    Malinke1 (1.4)0 (0.0)1 (2.0)1 (2.0)3 (1.3)
No. (%) of individuals with P. falciparum-positive smear at enrollment4 (5.5)4 (7.7)5 (9.8)3 (6.1)16 (7.1)
Level of parasitemia if smear was positive at enrollment (no. of parasites/μl) (geometric mean [95% CI])1,438 (159-12,973)3,616 (1,500-8,715)415 (134-1,287)953 (39-23,382)1,137 (579-2,232)
No. (%) of individuals positive for gastrointestinal helminths at enrollmenta9 (13.0)4 (8.3)4 (9.3)0 (0.0)17 (9.0)
No. (%) of individuals positive for urine schistosomiasis at enrollmentb0 (0.0)0 (0.0)2 (4.3)9 (28.1)11 (6.0)
Hemoglobin level at enrollment (g/l) (mean ± SD)11.2 ± 1.211.8 ± 1.012.3 ± 1.113.6 ± 1.412.1 ± 1.5
Distance lived from clinic (km) (mean ± SD)0.39 ± 0.110.40 ± 0.140.37 ± 0.100.36 ± 0.090.38 ± 0.11
No. (%) of individuals who used bed netsc21 (28.8)16 (30.8)9 (17.6)15 (30.6)61 (27.1)
No. (%) of individuals with hemoglobin typed
    AA50 (72.5)43 (86.0)35 (68.6)32 (76.2)160 (75.5)
    AS8 (11.6)4 (8.0)5 (9.8)5 (11.9)22 (10.4)
    AC10 (14.5)3 (6.0)11 (21.6)5 (11.9)29 (13.7)
    CC1 (1.5)0 (0.0)0 (0.0)0 (0.0)1 (0.5)
  • a Data available for 190 subjects.

  • b Data available for 184 subjects.

  • c Nightly bed-net use was self-reported at the end of the malaria season.

  • d Data available for 212 subjects.